A phenomenological contact-element model considering slight non-uniform contact for pounding analysis of highway bridges under seismic excitations

Impact stiffness is an important parameter of the contact-element models for the analysis and prediction of the pounding responses of highway bridges subjected to seismic excitations. This paper presents a pounding experiment to investigate the inconsistencies between the theoretical and experimental values of the impact stiffness both for the linear impact model and Kelvin impact model presented in literature. The analysis of the impact acceleration and acoustic emission signals indicates that accelerometer performance and the non-uniform pounding are two important factors that affect the pounding responses. Based on this observation, a phenomenological contact-element model is proposed based on the actual contact state of highway bridges during the impact. To evaluate the effectiveness of the proposed impact model, a numerical simulation is subsequently conducted. A comparison of the results indicates that the proposed impact model can effectively predict the pounding responses of highway bridges.